Troughing idler



June 5, 1951 H. T. SHANK TROUGHING IDLER Filed Nov. 21, 1947 ATT'YS Patented June 5, 1951 UNITED STATES PATENT OFFICE TROUGHING IDLER Harvey Tillman Shank, Toronto, Ontario, Canada Application November 21, 1947, Serial No. 787,293 1 claim. `(C1. 19a- 192) This invention relates to a troughing idler for a belt conveyor of the class in which a coil spring is employed as the idler member.

Troughing idlers in which the belt supporting idler element is formed from a coil spring have been known for a long time. They are superior in many respects to the more common troughing idler which comprises a plurality of unyielding pulleys rotatably mounted beneath the conveyor belt with their principal axis of rotation in the form of a trough. For example, the bending strain on the belt due to the troughing of the belt is more evenly distributed in the coil type idler thanv `in the type having a series of troughed rollers".v Also, due to the gradual troughing obtainedgwith a coil type idler, a greater load can be carried without spilling. In spite of these advantages obtainable with the coil type idler, it has not come into general use because the rotating-spiral coils continually tend to carry the conveyor belt sideways, oli of the idlers. This trouble is especially prevalent when the conveyor operates at no load. I have invented a coil type troughng idler which overcomes this great disadvantage in coil idlers.

It is then an object of my invention to pro-` vide a'coil type troughing idler which will not force the conveyor belt sideways oi of the idlers.

It is a further object of the invention to provide a simple means for constructing a coil type troughing idler having the above characteristics.

It isV also an object of the invention to provide a coil'type troughing idler which will not force the conveyor belt sideways, which is cheap to manufacture.

i It isa still further object of the invention to provide a troughingidler of the spring type having'a means in connection therewith for taking up spring fatigue.

With these and other objects in View a troughing idler according to my invention has a coil springfzidler member which is formed from its centre, 5in a right handed coil towards one end and a left hand coil towards its other end. Theqidler coil is then mounted beneath a conveyor belt which causes it to rotate in such a direction that each edge of the belt is urged onto the idler due to the rotation thereof. The invention will be clearly understood after reference to the following detailed specification taken in conjunction with the accompanying drawings.

In the drawings:

Figure 1 is a front view lof a troughing idler according to this invention.

Figure 2 is a partly broken away view ofthe troughing idler shown in Figure 1 carrying ya load.

Figure 3 is an enlarged sectional View from the top showing the members used for mounting the idler coil in its end supports. y

Figure 4 is a sectional View showing a mandrel for forming an idler coil according to the invention.

Figure 5 shows the construction of the centre'of an idler coil according to this invention.

' Referring to the drawings, numeral A indicates a troughing idler according to this invention generally. It comprises a coil spring idlerl I, rotatably mounted between the rigidly `4mounted spaced apart end supports 2 and 3. A conveyor belt 4 travels over the spring idler I. f

Specific reference will first be made. to the coil spring idler I. It is preferably made from a single piece of spring wire which is formed from a straight portion 5 adjacent its centre, ina right handed helix la towards one end, and a left handed helix Ib towards the other end,l the right the straightvportion 5, from which the right handed helix la and the left handed helix Ib are turned, at a slight incline to the longitudinal axis of the coil idler I when it is in an unflexed position as shown in Figure l. This. permits the rst turn from the centre in each of the'` helical portions Ia and Ib to lie closer to each other without interfering with the straight portion 5.

Reference will next be made to the manner in which the coil spring idler 'l is rotatably mounted 'between the rigidly mounted end supports 2 and 3. This is effected through similar bearing cups 6 and l which are inserted into the, open ends 8 and 9`of the idler I. .The idler coil is mounted in the same way at either end andtherefore only the mounting of the right handed portion Ia of the coil I Will be described in detail.

'I'he bearing cup 6 fits into the open end of the -coil springidler I and is locked therein in any suitable manner. In the embodiment of the invention shown, the cup 6 and end of the spring Ia are bored as at I0 and II respectively to receive a pin I2 when the two bores are aligned.

The shank I4 of the T-section bolt I5 passes through a circular opening I6 formed by the in terior annular shoulder I'I of the bearing cup 6. The end of the shank I4 is threaded as at I8 to receive a nut I9. The nut I9 is designed to hold the thrust ball-bearing 20 between it and the annular internal shoulder I'I of the bearing cup 6, and is locked in position by the Cotter pin 2I. Numeral 22 indicates a plate adapted to form an inner oil seal for the bearing cup 6, and is secured thereto by any suitable manner suchas the sniing'washerit. A suitable .oil :sealz24af is preferably employed 'around""the" shoulder I 'I to seal thedouter end of the bearing cup 6. The cup can be lubricated through the hole 24a.

The top portion 25 of the T-bolt ldsipircular in crossLsection and is designed for mounting in a complementary recess EGi-in'fthe-f-upperfportion of the end support 2, the shanlportion Ill being adaptedl to extend through a longitudinal slot (not shown) in the end support Wherebyto-per-rnit the cup to pivot vertically when a load delects the Thev operationof-the mountingewillfbeiapparent. hei-bearing cuphirotateswith thedrller pring I.

:.bolt-z I-,5.{V In@this l-connectiom' thev outerabearing race 2 la bears against the annular shoulder,- I'I ',.fandgithe-.yinner racer-2 9b bears; aga-insti the-'mut I S while theaballabearings we rper-miti gfree-fizelativelj :rotationsbetween.the two. The bolt I Seis kfree to @pivotverticallyinlits: mountingtas load-fisapplied :itodeflect the conveyor.

,.Jligutes` 1' and 2.of the `drawingsWill-serve to z -fexpla-in the operation of. the unit .as awhoie. The

conveyor belt 4 moves-out .of thepage to. cause ,the idler I ftoffrotateilfirr a'ffcloclrwise;;trection when avviewed-@frometlae deft side, that -is romlitheeside ifofftheyend `'sup-,port 2. fIt twill be gap-parentrthat rtl-'le spiralcoils ofteachrofxthe rotating-.espiral 10.011,:40,

sections I cte-land y I b will both tendzf-lto urge the irrespective.' halves-,of fthe. kconvey'on` belt 4, A.which l id-ler I tQeX downwardly.

The end support 3 is.,preferahlyfmade adjfuste ,able. .with. respect, to-v the end,suppf \rt,A Zliandyto .,thisiiendl theiholts; 2 .Whchesecure .itf to the. 110,01, ,passithrough ,longitudinal slots. Toladjustgthe .zesupnortx `with frespecttor'the support 21 itlis ,only

i the passage 'therethroughrfof the'wire;or other material from'which thecoil spring idler I-;is'.to be formed, `which inithe `embodiment shown, come -prisesfafsloti 32, The lslot)-3lipass'esfthrough.the "Iicngitu-dinal axes-of Y,theirrlandrel 29.

To form an idler coil with this mandrel, the centre of the wire length from which the idler is to be formed is passed through the slot or passage 32 with its free ends projecting therefrom. One of the free ends is then coiled in a right-handed coil towards one end of the mandrel While the other free end is coiled in a left-handed coil of equal length and'pitch towards the other end of the mandrel.

,.-As Vmentioned-.fabove, :L the, Straight/@portion 5 ad- `jacent the centre of the ncoilidler I'f' is preferably formed at an incline to the longitudinal axes "thereof, In this connection the slot 32 can be formed with its bottom 33 at an incline to the longitudinal axes of the mandrel. It is under- `stood,--of-course,' that in the coil winding operation the straight portion 5 of the wire is maintained against the bottom 33 of the slot 32 in order .to locate it at the centre of the resulting spring idler.

-Frorn-.thef-above, -itwill,beIapparentgthat' have disclosed a newconstructioir-for avcoilid-lerwhich completely fulfillsf-the@ objectsfof :invention iMy.' inventivefidea isthe form ngof-the,` mandrel --.with, a Ileft f handedgand".y wright Fha-miredv coilfextendingv--from-each side ofsitscentre-point- I haves-hown one,fembodimentfofi,thisffinventcnein ,.mi/.fspecication Other embodiments v...w-ill abe apparent.,tothoseskilledintheart. zdoynot intend,l therefore, that my invent ion shouldbe I restricted in scope-.to thefembodiment show-mex- -cept forstherestrictions expressed Tloyithe v`ollowl ing claim.

Vfhat Iclaim-as my. invention-. is: Y

In `a Vcolfiveyorridler, ,ar coil spring.` .id-leror-med, from itsV centre, finta@ righthanded ,-coil towards one end,-and in a leftrhanded coil towards ,the etherfendmthepitch-of i:saiclflriglit lyianyded coil ybeing-k the lsame` as they-pitch V0i" Y, said. lefth ded coilfthe pitch-of each offsaiidf-'righ handed nd 4Qleft handedf-portions of-said o i eingasmaller adjacent the:'centre fof-;sa-id coi spring, ,landcup means carried-:by each :Gnd .Offaidfcil felt; rotatab1y ;mountingfititofsupport, the conveyor.

REFERENCES CITED 'The'-r following references a-refoiL Vrecord j-in'-'rthe flle of thisf Apatent z piece "cylindrical" mandrel, "the s e'ction 3 I 'tting i' 60 UNITED. `STA'IESTl?,'IENTS -Number sName Date '857-3510 .Dull 1907 ,-85.7l772 .'lh'omas une.,f 2o,;z11907 1,417 1,148 Simonsen :Feb i916 1,189,846 Lockwood '.Ju1y. 4,f, 1916 ,1,483,985 Price 1,710,634 Schl'ach A131223, .1 929 11980,*7'77 "Zollinger `Nov. l 3, 1934 2,391,178 Mci/might inemiagglefis 1 FOREIGN RATE-NTS fNumber Country '{Date 496,987 Great Britain BecSiS; 1935 ::672;2l8 ermany F='Feb.l22,f 939 

